Vacuum IG window unit with metal member in hermetic edge seal

ABSTRACT

A vacuum insulating glass (IG) unit and/or a method of making the same is/are provided. In certain example embodiments, the edge seal includes at least one metal member located between the opposing substrates (e.g., glass substrates). The at least one metal member may be bonded to the glass substrate(s) via a bonding material such as solder glass, frit and/or the like. The provision of the at least one metal member in the edge seal, between and/or exterior the glass substrates, is advantageous in that this provides for a more flexible edge seal permitting more give and take during window flexing in different environmental conditions. The additional flexibility of the edge seal may reduce the amount of optical distortion caused by flexing of the window, and/or the likelihood of window breakage in certain environmental conditions.

This invention relates to a vacuum insulating glass (IG) unit, and amethod of making the same. More particularly, this invention relates toa vacuum IG unit including at least one metal member in an edge sealthereof.

BACKGROUND OF THE INVENTION

Vacuum IG (VIG) units are known in the art. For example, see U.S. Pat.Nos. 5,664,395, 5,657,607, 6,399,169, 6,641,689, 6,692,600 and5,902,652, the disclosures of which are all hereby incorporated hereinby reference.

Prior art FIGS. 1-2 illustrate a conventional vacuum IG unit. IG unit 1includes two spaced apart sheets of glass 2 and 3 which enclose anevacuated or low pressure space 6 therebetween. Glass sheets 2 and 3 areinterconnected by peripheral or edge seal of fused solder glass 4 and anarray of support pillars or spacers 5.

Pump out tube 8 is sealed by solder glass 9 to an aperture or hole 10which passes from an interior surface of glass sheet 2 to the bottom ofrecess 11. A vacuum is attached to tube 8 so that the cavity betweensheets 2 and 3 can be evacuated to create a low pressure area 6 betweenthe opposing glass substrates. After evacuation, tube 8 is melted toseal the vacuum. Recess 11 retains melted and sealed tube 8. Chemicalgetter 12 may be included within machined recess 13. Alternatively,although not shown, the pump-out tube or hole may be located in the edgeseal instead of in one of the glass substrates 2, 3.

In prior art FIGS. 1-2, edge seal 4 is made entirely from solder glass.For example, see U.S. Pat. No. 5,902,652. As explained in the '652patent, the solder glass edge seal is formed by depositing the solderglass as a liquid slurry onto the surface of one or both of the glasssheets 2, 3. The glass sheets 2 and 3 are then brought together and theentire unit is then heated to a temperature at which the solder glassmelts, wets the surface of the glass sheets, and flows to produce ahermetic edge seal 4 between the glass sheets 2 and 3.

Unfortunately, the edge seal 4 of FIGS. 1-2, made entirely of solderglass and directly contacting both glass substrates, is disadvantageousin certain situations. During many environmental conditions in which theVIG unit may be used (e.g., during hot, cold, and/or windy conditions),there tends to be much flexing of the vacuum IG window unit. The natureof the edge seal 4 in FIGS. 1-2 causes such flexing to distort theoptics of the window unit, and breakage of the window unit is evenpossible in extreme conditions.

It is apparent from the above that there exists a need in the art for avacuum IG unit, and corresponding method of making the same, includingan improved edge seal between opposing glass sheets or substrates.

This invention will now be described with respect to certain embodimentsthereof, accompanied by certain illustrations.

SUMMARY OF EXAMPLE EMBODIMENTS OF THE INVENTION

In certain example embodiments of this invention, there is provided avacuum IG window unit including at least one metal member in an edgeseal thereof, and/or a method of making the same.

In certain example embodiments, the edge seal includes at least onemetal member located between the opposing substrates (e.g., glasssubstrates). In certain example embodiments, the metal member need notdirectly contact the glass substrates. In certain example embodiments,the at least one metal member is bonded to the glass substrate(s) via abonding material such as solder glass, frit and/or the like. Moreover,in certain example embodiments the metal member may have a coefficientof expansion similar to that of the glass substrates, with or withoutcoated surface(s). In certain example embodiments, the provision of theat least one metal member in the edge seal, between the glasssubstrates, is advantageous in that this provides for a more flexibleedge seal permitting more give and take during window flexing indifferent environmental conditions. The additional flexibility of theedge seal can reduce the amount of optical distortion caused by flexingof the window, and may also reduce the likelihood of window breakage incertain environmental conditions.

In certain example embodiments of this invention, there is provided athermally insulating glass panel comprising: first and second spacedapart glass substrates defining a low pressure space therebetween havinga pressure less than atmospheric pressure; a plurality of spacersdisposed between said first and second glass substrates in order tospace the substrates from one another; and a hermetic edge seal disposedat least partially between said first and second glass substrates forhermetically sealing said low pressure space, wherein said edge sealcomprises at least one substantially U-shaped metal member that isbonded to each of the first and second glass substrates.

In other example embodiments of this invention, there is provided athermally insulating glass panel comprising: first and second spacedapart glass substrates defining a low pressure space therebetween havinga pressure less than atmospheric pressure; a plurality of spacersdisposed between said first and second glass substrates in order tospace the substrates from one another; and a hermetic edge seal disposedat least partially between said first and second glass substrates forhermetically sealing said low pressure space, wherein said edge sealcomprises first and second metal members that are bonded to each otherto form a laminate which is bonded to the first and second glasssubstrates.

In still further example embodiments of this invention, there isprovided a thermally insulating glass panel comprising: first and secondspaced apart glass substrates defining a low pressure space therebetweenhaving a pressure less than atmospheric pressure; a plurality of spacersdisposed between said first and second glass substrates in order tospace the substrates from one another; and an edge seal disposed atleast partially between said first and second glass substrates forhermetically sealing said low pressure space, wherein said edge sealcomprises at least one metal member that does not directly contacteither of the glass substrates and which is continuous and forms a ringaround and/or proximate an entire periphery of the panel.

IN THE DRAWINGS

FIG. 1 is a prior art cross-sectional view of a conventional vacuum IGunit.

FIG. 2 is a prior art top plan view of the FIG. 1 vacuum IG unit, takenalong the section line illustrated in FIG. 1 with the peripheral or edgeseal being shown in cross-section.

FIG. 3 is a cross sectional view of a vacuum IG unit according to anexample embodiment of this invention.

FIG. 4 is a cross sectional view of a vacuum IG unit according toanother example embodiment of this invention.

FIG. 5 is a cross sectional view of a vacuum IG unit according to yetanother example embodiment of this invention.

FIG. 6 is a cross sectional view of a vacuum IG unit according toanother example embodiment of this invention.

FIG. 7 is a cross sectional view of a vacuum IG unit according toanother example embodiment of this invention.

DETAILED DESCRIPTION OF CERTAIN EXAMPLE EMBODIMENTS OF THIS INVENTION

Referring now more particularly to the accompanying drawings in whichlike reference numerals indicate like parts throughout the severalviews.

FIGS. 3-5 are cross sectional views illustrating vacuum IG window unitsaccording to different example embodiments of this invention. The topview may be similar to that shown in FIG. 1 in certain exampleinstances, for purposes of example and without limitation. Thus, theedge seal 20 may be provided around all sides of the VIG unit in certainexample instances. Because interior space 6 between the opposingsubstrates 2, 3 is at a pressure lower or less than atmospheric ingeneral, this type of panel is often referred to as a vacuum insulatingglass (IG) or VIG unit. An optional pump out tube or hole (not shown)may be disposed in a hole or aperture formed in either one of thesubstrate or the edge seal in certain example instances, for permittingthe space 6 to be evacuated to low pressure. Edge seal 20 hermeticallyseals the low pressure space 6 between the substrates 2, 3 in certainexample embodiments.

Referring to FIGS. 3-5, in certain example embodiments, an edge seal 20of a vacuum IG window unit includes at least one metal member 21 and/or22 located between the opposing substrates 2 and 3 (e.g., glasssubstrates). In certain example embodiments, the metal member 21 and/or22 need not directly contact the glass substrates 2 and/or 3. In certainexample embodiments, the metal member 21 and/or 22 is bonded to theglass substrate(s) 2 and/or 3 via an adhesive or bonding material 25such as solder glass, solder glass frit, and/or the like. Moreover, incertain example embodiments the metal member 21 and/or 22 may have acoefficient of expansion similar to that of one or both of the glasssubstrates 2, 3, with or without coated surface(s).

In certain example embodiments, the provision of the at least one metalmember (which may or may not be a metal alloy) 21 and/or 22 in the edgeseal 20, between the glass substrates 2 and 3, is advantageous in thatthis provides for a more flexible edge seal 20 permitting more give andtake during window flexing in different environmental conditions (e.g.,windy conditions, hot/cold temperature changes, etc.). This additionalflexibility of the edge seal 20 can reduce the amount of opticaldistortion caused by flexing of the window, and may also reduce thelikelihood of window breakage in certain environmental conditions.

In certain example embodiments of this invention, the VIG unit isprovided with a metal or metal alloy member(s) 21/22 inclusive edgesseal 20 with a similar coefficient of expansion to soda-lime-silicabased glass which may be used for one or both of the glass substrates 2,3. A low temperature ceramic frit 25, which may be applied insemi-liquid, liquid, paste and/or slurry form to the glass, can be usedto bond the metal member 21 and/or 22 to the glass 2 and/or 3. The useof such a material for the edge seal may optionally permit lowerprocessing temperatures to be used; this in turn may optionally allowfor the use of commercially processed thermally tempered glass, with orwithout a low-E coated surface(s), to be used for substrate(s) 2 and/or3. In certain example embodiments, the heating process used to seal themetal inclusive edge seal 20 may allow the use of tempered glass forsubstrate(s) 2 and/or 3, without losing substantial temper propertiesduring the fabrication process.

“Peripheral” and “edge” seals herein do not mean that the edge seals 20must be located at the absolute periphery of the unit, but instead meanthat the edge seal is at least partially located at or near (e.g. withinabout two inches) an edge of at least one substrate of the unit and mayor may not be located at the absolute edge periphery of the unit.

In certain example embodiments substrates 2 and/or 3 are substantiallytransparent to visible light (i.e. at least about 50% transparent, morepreferably at least about 70% transparent, more preferably at leastabout 80% transparent, and most preferably at least about 90%transparent); although they may be deeply tinted in other embodiments.Edge seal 20 may be located entirely between the opposing substrates 2and 3, or alternatively only partially between the substrates if theedge seal should happen to bulge or be squeezed outwardly to some degreeduring manufacture, or even possibly at least partly external to one orboth substrates 2, 3.

Vacuum IG units such as those shown in FIGS. 3-5 according to differentembodiments of this invention may be used as residential or commercialwindows. The evacuation of space 6 eliminates or reduces heat transportbetween glass substrates 2 and 3 due to gaseous conduction andconvection. In addition, radiative heat transport between glass sheets 2and 3 can be reduced to a low level by providing a low emissivity(low-E) coating(s) (not shown) on the internal (or external) surface ofone or both of sheets 2, 3. High levels of thermal insulation can thusbe achieved. While the pressure in low pressure space 6 is generallyless than atmospheric pressure, in certain embodiments the pressure inspace 6 is reduced to a level equal to or below about 0.5×10⁻³ Torr,more preferably below about 0.1 mTorr, or 10⁻⁴ Torr, and most preferablybelow about 10⁻⁶ Torr of atmospheric pressure. Edge seal 20 reduces oreliminates any ingress or outgress of gas or air to/from low pressurespace 6. A plurality or an array of spacers 5 is provided between thesubstrates 2, 3 to space them from one another. Spacers 5 may becircular in shape, cylindrical in shape, rectangular in shape, oval inshape, round in shape, or linearly elongated in shape in differentembodiments of this invention. Spacers 5 may be made of, for example,glass, sapphire, steel, metal or metal alloy, glass fibers, or any othersuitable material in different embodiments of this invention.

In the FIG. 3 embodiment, the edge seal 20 includes first and secondmetal (which includes a possible metal alloy) members 21 and 22. Themetal members 21 and 22 may be substantially planar in shape in certainexample embodiments, and may define planes substantially parallel to theglass substrates 2 and 3 in certain example embodiments. In making theVIG unit of FIG. 3, metal member 22 is bonded to glass substrate 2 viabonding material 25 (e.g., low temperature solder glass frit or thelike), and metal member 21 is bonded to glass substrate 3 via anotherportion of bonding material 25. Each bonding material portion 25 may ormay not be the same in certain example instances. Then, after the metalmembers 21 and 22 have been bonded to their respective correspondingglass substrates 3 and 2, the two glass substrates are brought towardeach other and the metal members 21 and 22 are brought together andbonded to each other via laser welding, ultrasonic bonding, or the like,so as to ultimately form a laminated metal member in the final VIG unit.Again, this seal 20 may possibly extend around the entire periphery ofthe VIG unit in certain example embodiments, as shown in FIG. 1.

Metal members 21 and 22 may or may not be made of the same material incertain example embodiments. Example metals which may be used formember(s) 21 and/or 22 include stainless steel, Cr, alloys includingthese or other metals, or any other suitable metal. Small amounts ofnon-metals may also be present in the metal member(s) 21 and/or 22 incertain example instances.

In the FIG. 4 embodiment, a substantially U-shaped metal (which may beof a single metal or a metal alloy in different instances) member 21 isused and is bonded to both glass substrates 2 and 3 via a bondingmaterial 25 such as solder glass frit. The substantially U-shaped metalmember 21 includes first and second approximately parallel legsconnected to each other via a base which may or may not be curved. Eachleg of member 21 may be aligned substantially parallel to the adjacentglass substrate as shown in FIG. 4, in certain example embodiments ofthis invention. The substantially U-shaped metal member 21 may bealigned so that the open-side of the U faces inwardly toward lowpressure space 6 in certain example instances as shown in FIG. 4, oralternatively in other example embodiments the open-side of the U mayface outwardly away from space 6 in certain instances. The interiorcavity 33 defined between the opposing legs of substantially U-shapedmember may or may not be filled with bonding material 25 in differentexample embodiments of this invention. Filling or substantially fillingof cavity 33 with bonding material 25 may be advantageous in certainexample instances to provided additional stability to the edge seal,whereas not filling the cavity 33 with bonding material 25 may beadvantageous in that additional flexibility of the edge seal may beprovided. In the FIG. 4 embodiment, the member 21 may be bonded tosubstrate 2 first and thereafter to substrate 3, or vice versa, oralternatively may be bonded to both substrates 2, 3 at the same time ina common heating step for bonding material 25.

In the FIG. 5 embodiment, the metal member 21 is made up of a singlemetal member that is bonded to both substrates 2 and 3 via bondingmaterial 25. The metal member 21 in the FIG. 5 embodiment may be fairlythick (e.g., thicker than 21 and 22 in the FIG. 3 embodiment forinstance) in certain example embodiments. In the FIG. 5 embodiment, themetal member 21 may be bonded to substrate 2 first and thereafter tosubstrate 3, or vice versa, or alternatively may be bonded to bothsubstrates 2, 3 at the same time in a common heating step for bondingmaterial 25.

In each of the FIGS. 3-5 embodiments, the metal member 21 (and possibly22) may be made of a continuous member that forms a ring around orproximate the entire periphery of the VIG unit as shown in FIG. 1.Alternatively, in other example embodiments, the metal member 21 may bemade up of a plurality of connected or spaced apart different members ina given VIG unit. The metal members 21 and 22 preferably do not directlycontact the glass substrates 2, 3 in certain example embodiments,although in alternative embodiments it is possible that member 21 and/or22 may contact a glass substrate(s).

FIGS. 6 and 7 are cross sectional views of vacuum IG window unitsaccording to other example embodiments of this invention. In the FIG. 6embodiment and the FIG. 7 embodiment, the substantially U-shaped metalmember(s) 21 is provided partially or even entirely exterior of the gapbetween the substrates 2 and 3. In FIGS. 6-7, the metal member 21encapsulates the edges 41, 42 of the respective glass substrates 2, 3.In FIGS. 6-7, a substantial portion, or possibly all of, the metalmember 21 is located so as to be not between the substrates 2 and 3. Thelength of the spacer may or may not be crimped, dimpled, or the like inorder to facilitate expansion and/or contraction longitudinally orperpendicular to the glass edge.

It is noted that the metal member 21 may be made by providing aplurality of different metal members one along each side of the panel,and welding or otherwise joining the metal members at or proximatecorners of the panel in order to form one metal member 21. Moreover, aroll forming process may or may not be used in order to shape themember(s) 21 to desired length(s).

In certain example embodiments, the solder glass or frit may bepre-applied to the metal and/or glass surfaces, pre-fired, and then themember(s) 21 may be applied to the glass and re-firing in order to fusethe pre-applied frit. This may be used to shorten the heat cycle inorder to bond the frit between the metal and glass.

Once given the above disclosure, many other features, modifications, andimprovements will become apparent to the skilled artisan. Such otherfeatures, modifications, and improvements are, therefore, considered tobe a part of this invention, the scope of which is to be determined bythe following claims.

1. A thermally insulating glass panel comprising: first and secondspaced apart glass substrates defining a low pressure space therebetweenhaving a pressure less than atmospheric pressure; a plurality of spacersdisposed between said first and second glass substrates in order tospace the substrates from one another; and a hermetic edge seal disposedat least partially between said first and second glass substrates forhermetically sealing said low pressure space, wherein said edge sealcomprises at least one substantially U-shaped metal member that isbonded to each of the first and second glass substrates.
 2. The panel ofclaim 1, wherein said substantially U-shaped member includes first andsecond approximately parallel legs that are connected to each other witha base, and wherein the first leg is bonded to the first glass substrateand the second leg is bonded to the second glass substrate.
 3. The panelof claim 1, wherein said substantially U-shaped member is oriented sothat an open-side of the substantial U-shape faces inwardly toward thelow pressure space.
 4. The panel of claim 1, wherein said substantiallyU-shaped member is oriented so that an open-side of the substantialU-shape faces outwardly away from the low pressure space.
 5. The panelof claim 1, wherein substantially U-shaped member is continuous andforms a ring around and/or proximate the entire periphery of the panel.6. The panel of claim 1, wherein the substantially U-shaped metal memberis bonded to each of the first and second glass substrates using solderglass.
 7. The panel of claim 1, wherein the substantially U-shaped metalmember is bonded to at least one of the first and second glasssubstrates using low temperature ceramic frit.
 8. A thermally insulatingglass panel comprising: first and second spaced apart glass substratesdefining a low pressure space therebetween having a pressure less thanatmospheric pressure; a plurality of spacers disposed between said firstand second glass substrates in order to space the substrates from oneanother; and a hermetic edge seal disposed at least partially betweensaid first and second glass substrates for hermetically sealing said lowpressure space, wherein said edge seal comprises first and second metalmembers that are bonded to each other to form a laminate which is bondedto the first and second glass substrates.
 9. The panel of claim 8,wherein said first and second metal members are each substantiallyplanar in shape.
 10. The panel of claim 9, wherein said first and secondmetal members are each oriented substantially parallel to the first andsecond glass substrate, and wherein the first and second metal membersdirectly contact each other.
 11. The panel of claim 8, wherein saidfirst and second metal members do not directly contact any glasssubstrate of the panel.
 12. The panel of claim 8, wherein said laminateis continuous and forms a ring around and/or proximate the entireperiphery of the panel, and may optionally not be crimped in order toallow for expansion and/or contraction substantially perpendicular toedges of the glass sheet.
 13. The panel of claim 8, wherein saidlaminate is bonded to each of the first and second glass substratesusing solder glass.
 14. The panel of claim 8, wherein said laminate isbonded to at least one of the first and second glass substrates usinglow temperature ceramic frit.
 15. A thermally insulating glass panelcomprising: first and second spaced apart glass substrates defining alow pressure space therebetween having a pressure less than atmosphericpressure; a plurality of spacers disposed between said first and secondglass substrates in order to space the substrates from one another; andan edge seal disposed at least partially between said first and secondglass substrates for hermetically sealing said low pressure space,wherein said edge seal comprises at least one metal member that does notdirectly contact either of the glass substrates and which is continuousand forms a ring around and/or proximate an entire periphery of thepanel.
 16. The panel of claim 15, wherein said metal member issubstantially rectangular in shape when viewed in cross section.
 17. Thepanel of claim 15, wherein said metal member is bonded to at least oneof the first and second glass substrates using solder glass.
 18. Thepanel of claim 15, wherein said metal member is bonded to both of thefirst and second glass substrates using low temperature ceramic frit.19. A thermally insulating glass panel comprising: first and secondspaced apart glass substrates defining a low pressure space therebetweenhaving a pressure less than atmospheric pressure; a plurality of spacersdisposed between said first and second glass substrates in order tospace the substrates from one another; and a hermetic edge seal forhermetically sealing said low pressure space, wherein said edge sealcomprises at least one substantially U-shaped metal member that isbonded to each of the first and second glass substrates.
 20. The panelof claim 19, wherein at least a substantial portion of the substantiallyU-shaped metal member is not located between the first and second glasssubstrates.
 21. The panel of claim 19, wherein the substantiallyU-shaped metal member encapsulates at least parts of peripheral edges ofboth the first and second glass substrates.
 22. The panel of claim 19,wherein said substantially U-shaped member includes first and secondapproximately parallel legs that are connected to each other with abase, and wherein the first leg is bonded to the first glass substrateand the second leg is bonded to the second glass substrate.
 23. Thepanel of claim 19, wherein said substantially U-shaped member is locatedsubstantially between the first and second glass substrates and isoriented so that an open-side of the substantial U-shape faces inwardlytoward the low pressure space.
 24. The panel of claim 19, wherein thesubstantially U-shaped metal member is bonded to each of the first andsecond glass substrates using solder glass.